There's no magic number when it comes to exercise, but that doesn't mean numbers aren't important.
After all, numbers are easy, convenient things to remember. And because exercise is something that can be easily quantified, having numbers as symbols of how much exercise we should be getting can serve an important role in public health.
There's evidence to back it up too. A number of studies in recent years have shown that taking more steps on a daily basis is linked to less risk of early death, and it doesn't even matter where those steps come from.
Of course, every analysis is slightly different, and no two cohorts are the same.
Because of that, scientists keep making fresh, incremental discoveries about just how good walking X steps is for people, as well as identifying who stands to benefit, and by how much.
In the latest study to explore this territory, a team led by physical activity epidemiologist Amanda Paluch from the University of Massachusetts, Amherst tracked a cohort of over 2,000 middle-aged Black and White men and women, sourced from four different US cities.
The group, with an average age of just over 45, wore accelerometers that tracked their daily step count and step intensity during waking hours, as they went about their lives.
The experiment began back in 2005, and participants were followed up at regular intervals in the years up until 2018, by which point 72 of the original group had died.
While the observational nature of the study means we can't draw any firm conclusions about how walking did (or didn't) boost the health of the people in the experiment, it can identify links between levels of activity and health outcomes in the cohort overall.
Most importantly, the researchers found here that individuals taking at least 7,000 steps per day had an approximately 50 to 70 percent lower risk of early death when compared to those who averaged fewer than 7,000 daily steps in the experiment.
By itself, step intensity (measuring the quickness of steps taken) had no effect on mortality.
According to the researchers, increasing daily step volume among the least active people in the population may confer the greatest protection against mortality – but after a certain point, extra steps appear to have no beneficial effect, at least on that specific outcome.
"Taking more than 10,000 steps per day was not associated with further reduction in mortality risk," the researchers explain in their study.
While the findings broadly confirm much of what we already knew about walking benefits from previous studies, the new 7,000 steps threshold is certainly an easier target to hit than 10,000 steps for people who aren't walking at that level, and could stand to benefit the most from studies like this.
"Steps per day is a simple, easy-to-monitor metric and getting more steps/day may be a good way to promote health," Paluch told HealthDay News.
"7,000 steps/day may be a great goal for many individuals who are currently not achieving this amount."
Not that 7,000 steps is the magic number; nor is this the final number we'll likely be hearing about on this topic.
According to physical activity researcher Nicole Spartano from Boston University, in the near future we can actually expect to hear a lot more about how daily steps impact our health – thanks to a new generation of imminent studies using more recent accelerometer technology that wasn't available back in 2005.
"It is unclear the extent to which steps measured on [older] activity monitors compare with steps measured by common consumer devices, including smartwatches, pedometers, and smartphone applications," Spartano writes in an expert commentary on the new research.
"In the next few years, the number of articles published relating step counts to mortality will accelerate rapidly as many other large cohort studies have completed accelerometry measurement using a wide variety of research-grade accelerometer devices with 10 years of follow-up or more."
The findings are reported in JAMA Network Open.